Similar induction of the hepatic EGF receptor in vivo by EGF and partial hepatectomy.
A 2-fold increase in the level of epidermal growth factor (EGF) receptor mRNA accompanied by a similar increase in newly synthesized ligand-binding EGF-receptors was observed 2-4 h after intraportal EGF-injections and 2-4 h after partial hepatectomy. After this initial increase, the EGF-receptor levels decreased back to control levels 6-8 h after EGF-injections and below control levels 6-8 h after partial hepatectomy. EGF was also found to influence the degradation of endocytosed [125I]-EGF 3 h after injection to a similar extent as partial hepatectomy. The similar effects of EGF and partial hepatectomy suggests that EGF or EGF-like factors may be mechanistically involved in the early "promotion" stage during the pre-replicative phase of liver regeneration. The EGF-induced effects are, however, at least not alone responsible for the replicative process.
Johansson
S
S
Department of Pathology, Karolinska Institute, Huddinge University Hospital, Sweden.
Andersson
G
G
D000818:Animals; D004247:DNA / Q000096:biosynthesis; D004705:Endocytosis; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008115:Liver Regeneration; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011919:Rats, Inbred Strains
D012333:RNA, Messenger; D004815:Epidermal Growth Factor; D004247:DNA; D066246:ErbB Receptors